The present application relates generally to power distribution systems and, more particularly, to a current and voltage module and methods of monitoring current and voltage in power distribution systems.
Known electrical distribution systems include one or more circuit breakers that are each coupled to one or more loads. The circuit breakers are controlled based upon current flowing through the circuit breakers sensed by current sensors. For example, the circuit breaker causes current flow to be interrupted if the current is outside of acceptable operating conditions.
In addition to measuring current, at least some known circuit breakers also measure voltage. Voltage may be measured either as an amount between phase conductors and/or as an amount being applied to a load. The voltage measurement may be used for metering and/or protection purposes. To obtain a voltage measurement, some known circuit breakers include metal contacts, or taps, molded in a housing of the circuit breaker to tap off voltage. A hard wire connection is made from the taps to a circuit breaker trip unit. However, such taps may interfere with the circuit breaker's internal conductors, which may cause the connection with the conductors to weaken and/or fail over time. Additionally, the hard wire connection necessitates the use of costly, high-voltage wires to handle the large voltages being measured. The wires may also present dielectric issues because they are at the same voltage potential as the conductors. Moreover, some known circuit breakers lack the space needed for voltage attenuation and/or step-down transformers, while also maintaining sufficient dielectric strength within the insulation layer to prevent breakdown due to the high voltage levels.